The present invention relates to a ball swivel joint for rotatably mounting a structure on a support of an excavator, rotatable crane and the like. More particularly, it relates to a swivel joint including two ring members having spherical grooves in which two rows of balls are received.
Swivel joints of the above-mentioned general type have been proposed in the art. In an excavator or the like such a swivel joint must take up forces acting in various different directions under conditions in which there is no central connection between the upper rotatable structure and the lower immovable support of the machine which are connected by the joint. To make this possible, a swivel joint has been proposed which consists of three parts arranged one above the other and is provided with two rows of balls, as disclosed in the German patent 947,240. Such a construction is complicated and is difficult to manufacture when large diameters are required. It also has the disadvantage that a force which acts from a respective side of the swivel joint is taken up by only one row of the balls in dependence upon the side from which the force is applied.